There are no such things as applied sciences, only applications of science.

Messieurs, c'est les microbes qui auront le dernier mot." (Gentlemen, it is the microbes who will have the last word.)

In good philosophy, the word cause ought to be reserved to the single Divine impulse that has formed the universe.

Inspiration is the impact of a fact on a well-prepared mind

Without theory, practice is but routine born of habit. Theory alone can bring forth and develop the spirit of inventions.

Whether our efforts are, or not, favored by life, let us be able to say, when we come near to the great goal, I have done what I could.

If science has no country, the scientist should have one, and ascribe to it the influence which his works may have in this world.